1. Field of the Invention
The present invention relates to linear form, fill and seal packaging machines. Specifically, the present invention relates to a packaging machine which may be easily converted from processing one carton cross-section to processing another carton cross-section, and to a packaging machine capable of processing two different size cartons at once.
2. Description of the Related Art
Packaging machines are known that integrate into a single unit the various components necessary to form a container, fill the container with a liquid product, and seal the container. Such packaging machines typically first transfer carton blanks from a magazine onto a mandrel of the machine for bottom forming of the cartons. The carton blank is erected in transit from the magazine to the mandrel. The erected and bottom formed carton is then placed on a conveyor line and in an indexed motion, conveyed to various stations along the packaging machine. The cartons are held in place by a plurality of carton guides connected to a conveyor chain. The carton guides are set to tightly hold each of the cartons in a predetermined position. Several optional stations are fitment application stations and sterilization stations. Required stations, usually downline from these optional stations include a filling station and a top sealing station. At the filling station, each of the cartons is filled with a product dispensed from a product storage tank. Bottom-up filling is a preferred processing technique in which the carton is lifted up to the filling nozzle/tube and then filled as it is lowered therefrom. From the filling station, the carton proceeds to a top sealing station where the top of the carton is folded together and then sealed either ultrasonically or through heat. The carton is then ready for distribution.
In order to increase production capacity, some of these packaging machines have ben configured with two processing lines. An example of such a machine is the TR/8 TETRA REX.RTM. packaging machine available from Tetra Pak, Incorporated of Chicago, Ill. which is described in U.S. Pat. No. 4,790,123 for a Method And A Machine For The Manufacturing Of Packing Containers, issued on Dec. 13, 1988 which is hereby incorporated by reference. These dual line machines would have the very same processing stations on both lines. For example, line one would have a filling station and line two would have the same exact filling station. This was because both lines were driven off a single cam drive located beneath the platform of the packaging machine. The single cam drive would engage with a number of cams and gears to operate the various stations along the packaging machine. In one embodiment, when one line was active, the other line was inactive.
Current servomotor technology has allowed for the "individuality" of the various stations thereby allowing them independence from the single cam drive for performing their functions. However, servomotors have failed to completely render both lines on a dual line machine independent of each other.